I have this exact same issue and went to Apple this week.
Scenario:
Two Homepod minis with Version 17.1 went totally unresponsive at the same time.
I couldn't connect or manage them with Apple Home (Homekit) and I could not control them manually. Therefore even the reset with an iPhone or a manual reset on the Homepod itself was not possible.
Based on Apples Help Page, a Reset with a Macbook should be possible within the Finder, but nope.
Conclusion:
An Apple employee of the Genius Bar tried it's luck, but could only recreate the problem.
In an internal Knowledge Database he found out, that dispite the public info on the help page, a reset with a macbook is not possible.
He could only offer me to replace one of the Homepod minis under the terms of the legal warranty (here in Germany, idk which laws exists in other countries). But the other Homepod mini of mine is lost, because it is older than 2 years and will not be replace within the legal warranty.
He clearly said that he sees it as a failure of some kind but still couldn't help me. In some point I can understand that, on the other hand it is a pretty bad service if they analyze it as a problem of the product itself, but won't replace it.